To observe and explain an
acceleration vs. time graph when an object, in this case a
LabQuest 2 interface, is given an initial push and then allowed
to slide to a stop.
1. The area under the curve of an
a-t graph represents the change in velocity of an object. How
does the change in velocity as the LabQuest 2 is accelerated
compare to its change in velocity as it coasts to a stop?
2. Given the mass of the LabQuest 2 to be 350 grams, what
is the force of sliding friction between the LabQuest 2 and the
3. What is the coefficient of friction between the
LabQuest 2 and the table?
LabQuest 2, pamphlet*, rubber band*
Sensor: Internal X-axis
Rate: 100 samples/s Duration: 2.0 s or longer
* The rubber feet on the LabQuest 2 prevent it from sliding
smoothly across the table. Thus, in this photograph, the
LabQuest 2 is connected to the pamphlet with a rubber band that
goes through the middle of the book and it’s the friction
between the pamphlet and the table that operates to slow down
the sliding LabQuest 2. Another option is to cover the rubber
feet with pieces of smooth tape.
1. Verify that the value you
calculate for sliding friction is an accurate one.
2. If you have multiple LabQuest 2’s piled up on one another, or
added masses piled on the original LabQuest 2, how does this
affect your results?
3. Repeat the same experiment using a smart phone or tablet and
appropriate software to permit calculation of the area under the
acceleration vs. time graph.
4. Devise a way to repeat this experiment using computer-based
data collection or an original LabQuest. What sensor would you
use? Would this give you similar results or different results?
Idea contributed by Roger Larson from STEM Solutions in Boulder,
CO. Additional ideas and editing by Clarence Bakken.
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